Con Thien (Vietnamese: Cồn Tiên, meaning the "Hill of Angels") was a military base that started out as a U.S. Army Special Forces camp before transitioning to a United States Marine Corps combat base. It was located near the Vietnamese Demilitarized Zone (DMZ) about from North Vietnam in Gio Linh District, Quảng Trị Province. It was the site of fierce fighting from February 1967 through February 1968. Location Con Thien is located at (MGRS 48QYD113703) and was originally established as a Special Forces/CIDG camp on 20 February 1967 at Hill 158 by Special forces Det. A-110. The camp was built by a detachment from Naval Mobile Construction Battalion 4. and turned over to the 1st Battalion, 9th Marines, on 27 July 1967. Together with Marine bases at Gio Linh, Đông Hà and Cam Lộ, Con Thien enclosed the area known to the Marines as Leatherneck Square. Con Thien was intended to be used as a base for the McNamara Line to prevent People's Army of Vietnam (PAVN) infiltration across the DMZ. The firebase was strategically important because it offered unfettered views for 15 km east to the coast and north into North Vietnam. It was also very vulnerable because it was within range of PAVN artillery north of the DMZ which was largely immune to counter-battery fire. Early Border Operations On 27 February 1967, in response to Marine artillery fire into and the area north of the DMZ (Operation Highrise) PAVN mortar, rocket and artillery fire hit Con Thien and Gio Linh. On 20 March, the PAVN began shelling Con Thien and Gio Linh, which continued sporadically for the next two weeks. On 24 March 1st Battalion, 9th Marines began Operation Prairie III where they encountered a PAVN battalion in a bunker complex southeast of Con Thien. After a two-hour fight the PAVN withdrew leaving 33 killed in action. Sergeant Walter K. Singleton was posthumously awarded the Medal of Honor for his actions in the attack. 3rd Battalion, 3rd Marines operating beside 1/9th Marines encountered an entrenched PAVN Company, killing 28 PAVN including two women. On 30 March, Company I, 3rd Battalion, 9th Marines was establishing a night ambush position when it was attacked by a PAVN force, 2LT John P. Bobo was posthumously awarded the Medal of Honor for his actions during the attack. In mid-April Charlie Company, 11th Engineer Battalion was tasked with clearing a 200m wide strip